MAINTENANCE ALLOCATION CHART (MAC) - CONTINUED
Maintenance Functions - Continued
Calibrate. To determine and cause corrections to be made or to be adjusted on instruments or Test,
Measurement, and Diagnostic Equipment (TMDE) used in precision measurement. Consists of
comparison of two instruments, one of which is a certified standard of known accuracy, to detect and
adjust any discrepancy in the accuracy of the instrument being compared.
Remove/Install. To remove and install the same item when required to perform service or other
maintenance functions. Install may be the act of emplacing, seating, or fixing into position a spare,
repair part, or module (component or assembly) in a manner to allow the proper functioning of an
equipment or system.
Replace. To remove an unserviceable item and install a serviceable counterpart in its place. "Replace "
is authorized by the MAC and assigned maintenance level is shown as the 3d position code of the SMR
Repair. The application of maintenance services including fault location/troubleshooting,
removal/installation, and disassembly/assembly procedures, and maintenance actions to identify
troubles and restore serviceability to an item by correcting specific damage, fault, malfunction, or
failure in a part, subassembly, module (component or assembly), end item, or system.
The following definitions are applicable to the "repair" maintenance function:
Services - Inspect, test, service, adjust, align, calibrate, and/or replace.
Fault location/troubleshooting - The process of investigating and detecting the cause of
equipment malfunctioning; the act of isolating a fault within a system or Unit Under Test
Disassembly/assembly - The step-by-step breakdown (taking apart) of a spare/functional
group coded item to the level of its least component, that is assigned a SMR code for the
level of maintenance under consideration (i.e., identified as maintenance significant).
Actions - Welding, grinding, riveting, straightening, facing, machining, and/or resurfacing.
10. Overhaul. That maintenance effort (service/action) prescribed to restore an item to a completely
serviceable/operational condition as required by maintenance standards in appropriate technical
publications (i.e., DMWR). Overhaul is normally the highest degree of maintenance performed by the
Army. Overhaul does not normally return an item to like new condition.
11. Rebuild. Consists of those services/actions necessary for the restoration of unserviceable equipment to
a like new condition in accordance with original manufacturing standards. Rebuild is the highest degree
of material maintenance applied to Army equipment. The rebuild operation includes the act of
returning to zero those age measurements (e.g., hours/miles) considered in classifying Army